Preeclampsia is a leading cause of maternal and perinatal morbidity and mortality. As with other pregnancy problems, it is more common in black women. Our group proposed that preeclampsia results from endothelial dysfunction invoked by oxidative stress. A further proposal was that oxidative stress was due to reduced placental perfusion interacting with maternal factors. To test the relevance of these hypotheses to pregnant black women we measured lipids and a marker of oxidative stress, malondialdehyde. This was stimulated by the known association of dyslipidemia and oxidative stress and previous documentation of a more atherogenic lipid profile in nonpregnant black women. Paradoxically, black women had a more normal lipid profile but increased oxidative stress. The goal of this proposal is to confirm and explain this finding. We posit that this increased oxidative stress predisposes black women to preeclampsia and further propose that this is secondary to modifiable life style factors. There are no gold standards for oxidative stress, and to confirm the previous finding, other markers (isoprostanes, antibodies to ox-LDL, protein carbonyls and nitrosylated proteins) will be measured. The increase in oxidative stress between normal and preeclamptic black and white women will be compared. A smaller increase in blacks would support that preexisting oxidative stress predisposes to preeclampsia. Physiological and life style factors which might explain increased oxidative stress will be compared in pregnant black and white women. Women will be given a high fat meal and postprandial responses (lipid concentration and oxidation) compared. Nutritional and other modifiable life style factors which might contribute to oxidative stress will be examined. Thus, dietary history will be obtained and homocysteine (known to be associated with oxidative stress and preeclampsia) and its metabolic cofactor, folic acid, determined. Physical activity and lifestyle stress will also be assessed. Given the magnitude of difference in disease rates between black and white women, racial differences must be well characterized to serve as a basis for intervention. This study will contribute to a program of research directed at culturally-specific intervention during general health counseling, preconception counseling, and prenatal care for black women during the childbearing years, and potentially in later life.